Jurors found Matthew Nellessen guilty of first-degree murder Wednesday in the 2011 beating and stabbing death of his father in the family's Arlington Heights home.
They also found that his behavior was brutal and heinous, "indicative of wanton cruelty," and set the stage for a possible life sentence.
Nellessen, 22, showed no emotion after the verdict was announced.
Over the course of the trial, jurors heard graphic accounts of the murder of 55-year-old George Nellessen on April 12, 2011. They also viewed autopsy images of the widower's injuries, which prosecutors say were caused when Matthew Nellessen struck his father in the head with a baseball bat and stabbed him in the neck with a knife while he was bound to a chair in his family room.
In her closing arguments, Cook County Assistant State's Attorney Maria McCarthy said the evidence against the younger Nellessen was "overwhelming."
"All of his hatred and rage he had for his father came to a head in that family room," she said.
Jurors adjourned at 1:10 p.m. Wednesday after several hours of closing arguments during which Cook County Assistant Public Defender Daniel Naranjo insisted self-confessed Chicago gang member and star prosecution witness Marlon Green killed George Nellessen during a robbery -- and also intended to kill Matthew Nellessen, whom Naranjo described as polite and well-mannered.
Prosecutors, however, rejected the defense's characterization of Matthew Nellessen as a victim.
"Marlon Green was hand-picked by Matthew Nellessen when he came up with a plan to rob his father and needed someone like Marlon Green to help him do it," said McCarthy.
Green, who pleaded guilty to armed robbery and received an 18-year prison sentence in exchange for his testimony against Nellessen, would say anything to save himself, Naranjo said. The attorney said Green masterminded the crime, coerced Nellessen and controlled the situation.
Naranjo said Green held a pellet gun on the victim while Matthew Nellessen and co-defendant Armon Braden bound him to a chair in the family room of the Wilshire Lane home. The attorney also said Green accessed George Nellessen's financial accounts online and transferred money after the men forced the widower to divulge his user name and password. Green wrote out the $100,000 check payable to Matthew Nellessen, which the men forced George Nellessen to sign, Naranjo said.
And Green, after the murder, drove with Nellessen to Chicago's South Side -- Green's "turf," Naranjo said -- where they used the victim's ATM card to withdraw money.
"Marlon Green came here to testify not truthfully but conveniently," Naranjo said, adding that Green "stuck to his lies" until 2012 when he reached a deal with prosecutors.
"They had to pay the ringleader of a murder with the coins of amnesty," Naranjo said. "Let's hold this monster accountable for what he did."
Prosecutors dismissed the notion that Green orchestrated the robbery and murder.
"Mastermind? This is the guy who couldn't activate the cellphone he got at Walgreens," McCarthy said, referring to the purchases which receipts and surveillance video show Green and Nellessen made on the South Side the day after the murder.
"If Marlon Green planned on killing George Nellessen, he would have brought a gun, a real one," McCarthy said. "And George Nellessen would have gotten a bullet to the back of the head. Quick and clean."
As for Nellessen's claim that he was another Green victim, McCarthy pointed out that in the days after the murder, Nellessen never once asked for help. Not from the currency exchange clerk whom he asked to cash the $100,000 check, she said. Not from his friend Amanda Meinheit who testified she spent April 13, 2011, with Nellessen and Green. Not from the officers who took Nellessen into custody on April 14, 2011, after he led them on a chase from his father's home through Hoffman Estates, Barrington Hills and into East Dundee, McCarthy said.
"Are these the actions of a victim?" McCarthy asked. "Or someone who robbed and killed his father, who was enjoying his freedom and a little money and didn't want it to end."
Nellessen will be in court next on April 16.